Voicemails are a part of outbound calling but missed opportunities and awkward message drops don’t have to be. The Voicemail Detection feature helps your voice agent smartly identify when it’s reached a voicemail inbox and respond accordingly, avoiding awkward or wasted greetings, and optionally triggering automated follow-ups like SMS or email. This is especially useful in outbound call flows where pickup detection and timing are critical, such as sales outreach, appointment reminders, or lead qualification. 🧭 Path: Manage Agent → Customize tab → Voicemail Detection

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Why Voicemail Detection Matters

  • Improve agent experience by avoiding cutoff intros or beeps.
  • Save on costs by skipping unnecessary conversation attempts.
  • Boost user trust with professional, voicemail-appropriate responses.
  • Automate engagement by triggering SMS, emails, or workflows after detection.

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What It Does

When an outbound call is answered, your agent uses real-time audio cues to detect whether the recipient is a person or a voicemail system. Based on your configuration, it will either:
  • Retry voicemail detection,
  • Wait for the right moment to respond,
  • Speak a custom voicemail message,
  • Trigger automated follow-ups.

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What You Can Configure

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1. Max Detection Attempts

  • What it is: Number of times the system retries to determine if the call went to voicemail.
  • Why it matters: Helps balance detection accuracy vs. speed and cost.
  • Range: 1 to 5
  • Example: Setting this to 3 means the system will attempt detection up to 3 times before deciding.
Tip: Increase for better accuracy; decrease for faster calls and lower compute cost.

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2. Voicemail Playback Delay

  • What it is: Number of seconds the agent waits after voicemail is detected before speaking.
  • Why it matters: Prevents the agent from being cut off by long greetings or carrier beeps.
  • Range: 1 to 10 seconds
  • Example: A delay of 4 seconds gives enough time for most voicemail intros to end before the message plays.
Why delay?
Voicemail greetings can include:
“Hi, this is John. I’m not available right now…” [beep]
If your agent starts too early, its message may be lost.

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3. Voicemail Response

  • What it is: The message your agent will speak once voicemail is detected. You can also use dynamic variables in the message by using double curly braces like {{customer_name}}
  • Limit: 300 characters max
  • Example:
    "Hi, we tried reaching you but missed you. Please call us back or reply to this message."
Make it short, polite, and clear. Don’t include long messages. The goal is clarity, not conversation.

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4. Post Detection Actions

  • What it is: Optional actions your agent can take after leaving a voicemail.
  • Examples:
    • Send a follow-up SMS (e.g., “Just left you a voicemail. Text us back!”)
    • Send an email summary to the contact owner
    • Trigger a custom API
Use this to automate re-engagement or log activity in CRMs or backend systems.

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Bonus Tips & Best Practices

TipWhy It Helps
Keep initial greeting shortIf the bot’s first message is too long, it might overlap with the phone’s voicemail greeting, making it impossible to capture user audio or transcripts. Keep it concise, especially in the first 5–10 seconds.
Enable Barge-In DetectionTurn on Barge to let your agent listen while speaking. This improves voicemail detection accuracy, especially when voicemail systems start mid-sentence or play long intros.
Personalize the voicemail messageA natural, human-sounding message improves callback rates. Add a name or reason for the call.

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Example Scenario

  1. Agent makes an outbound call.
  2. No human detected → system retries 2 more times.
  3. Detection succeeds on attempt 3.
  4. Agent waits 5 seconds → speaks voicemail message.
  5. Triggers CRM update.

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When Should You Use It?

  • When your outbound calls frequently hit voicemail.
  • If you want to leave clean, professional messages without being cut off.
  • When you want to automate follow-up actions after voicemails.
  • To improve response rates by sending SMS/email right after missed calls.

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What This Feature Does Not Do (Yet)

  • It doesn’t guarantee 100% voicemail detection.
  • It won’t auto-detect specific voicemail messages (e.g., “the mailbox is full”).

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Best Practices

GoalSetting Recommendation
Max accuracyMax Attempts: 5, Delay: 4–5s
Faster call completionsMax Attempts: 1–2, Delay: 2–3s
Better callback rateAlways add Post Detection SMS or Email
Avoid being cutoffUse a delay of at least 3s

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Troubleshooting

IssueWhat to check
Agent speaks too earlyIncrease Voicemail Playback Delay
Message not playedCheck if detection attempt limit was too low
No follow-up actionsEnsure Post Detection Actions are configured properly